Per the official character description — which you first read about in a recent Ask Ausiello — Dr. Japeth Leeds is “a twisted, mysteriously brooding genius” whose talents include alchemy. But he becomes so obsessed with besting Franklin that he turns to the Dark Arts.

Crane and Leeds come face to face again in modern-day Sleepy Hollow, after Ichabod learns that the doctor “paid the ultimate price when one of his twisted experiments went awry.”

In addition to The Knick, Aitken’s TV credits include Madam Secretary and ITV’s Foyle’s War.

Aitken will appear in Episode 13. Sleepy Hollow returns — in its new timeslot — on Friday, February 5, at 8/7c.